Global kinetic modeling of the intrabinary shock in spider pulsars

其中最吸引人的天体是“蜘蛛脉冲星”，它是双星系统中一种非常快速旋转、非常致密的中子星。蜘蛛脉冲星被归类为红背星(RBS)或黑寡妇(BW)，它们处于紧密的双星轨道上，有一个低质量的恒星伴星。脉冲星发出强烈的相对论风。当风冲击伴星时，风加剧了伴星的烧蚀和质量损失，然后被脉冲星风“吞噬”-因此这些系统的名字令人想起。哥伦比亚大学的一个研究小组将使用最先进的计算机模拟来更好地了解蜘蛛脉冲星，以及一般的天体物理冲击波。这位首席研究员还将设计一门新课程--《封底物理学、天文学及以后》，向哥伦比亚大学博士生项目的学生介绍用定量的眼睛看现实的艺术，以个人经验和先验知识为指南，得出数量级的结论，从而准备做出基于定量推理的决定。相对论脉冲星风由相反磁场极性的环状条带组成，由热等离子体电流片隔开。风在强烈的激波中终止，脉冲星风的冲击波压力被伴风或其磁层平衡。双星内激波可能是粒子加速的有效场所，这就解释了为什么蜘蛛脉冲星的X射线和伽马射线光曲线经常受到轨道周期的调制。因此，对bw和rbs的仔细研究有助于揭示毫秒脉冲星中脉冲星风的基本未知的物理原理，并有助于理解从坡印亭通量主导流到粒子主导流的转变发生在哪里。这个项目将涉及蜘蛛脉冲星中双星内激波的第一原理全球动力学粒子-细胞模拟，因此人们可以同时捕捉磁场耗散、粒子加速和随后的发射的微观物理，以及激波的全球形态和曲率以及由此产生的宏观流动动力学。虽然主要关注的是蜘蛛脉冲星，但磁控条状激波中的粒子加速问题与其他系统中坡印亭磁通主导的相对论外流的物理学密切相关，比如活动星系核的喷流和伽马射线爆发。这一奖项推进了宇宙之窗大理想的目标。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Among the most fascinating astrophysical objects are the “spider pulsars,” which are a particular type of very rapidly-rotating, extremely compact neutron stars in a binary system. Spider pulsars, which are classified as either Redbacks (RBs) or Black Widows (BWs), are in tight binary orbits with a low-mass stellar companion. The pulsar emanates an intense relativistic wind. When impacting on the companion star, the wind exacerbates ablation and mass loss of the companion, which is then “devoured” by the pulsar wind --- hence, the evocative name of these systems. A research team at Columbia University will use state-of-the-art computer simulations to better understand spider pulsars, and astrophysical shock waves in general. The lead researcher will also design a new course, “Back-of-the-envelope physics, astronomy, and beyond," to introduce students in the Columbia Bridge to Ph.D. scholars program to the art of looking at reality with quantitative eyes, using personal experience and prior knowledge as a guide to drawing order-of-magnitude conclusions, and thus to being prepared to make decisions that are grounded in quantitative reasoning.The relativistic pulsar wind consists of toroidal stripes of opposite magnetic field polarity, separated by current sheets of hot plasma. The wind terminates in a strong shock, where the ram pressure of the pulsar wind is balanced by the companion wind or its magnetosphere. The intrabinary shock may be an efficient site of particle acceleration, which would then explain why X-ray and gamma-ray lightcurves of spider pulsars are often modulated on the orbital period. Therefore, the scrutiny of BWs and RBs can help uncover the largely unknown physics of pulsar winds in millisecond pulsars, and aid in understanding where the transition occurs from a Poynting flux-dominated to a particle-dominated flow. This project will involve first-principles global kinetic Particle-In-Cell simulations of the intrabinary shock in spider pulsars, so one can simultaneously capture the microscopic physics of magnetic field dissipation, particle acceleration and ensuing emission, as well as the global morphology and curvature of the shock and the resulting macroscopic flow dynamics. While the main focus is on spider pulsars, the question of particle acceleration in magnetically-dominated striped shocks is of profound relevance to the physics of Poynting-flux-dominated relativistic outflows in other systems, like jets of active galactic nuclei and gamma-ray bursts. This award advances the goals of the Windows on the Universe Big Idea.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.